Which of the following is not related to the calcium metabolism: March 2007

Ans. D i.e. None of the optionTwo hormones serve as primary regulators of the calcium in blood: parathyroid hormone and calcitonin.Parathyroid hormone stimulates bones to release calcium into blood, digestive tract to absorb more calcium and kidneys to excrete less calcium and activate more vitamin D.Calcitonin slows the release of calcium from bones (inhibits resorption)Other hormones which affects calcium metabolism are:1, 25-dihydroxycholecalciferolGlucocoicocoidsGrowth hormoneThyroid hormonesEstrogensInsulinCauses of hypercalcemia include:Overactivity of parathyroid glands: primary hyperparathyroidismCancer: lung and breast cancer, multiple myeloma, paraneoplastic syndromeMetastasis to bones also increases risk of hypercalcemia.Other diseases: tuberculosis and sarcoidosisMedications: lithium, Thiazide diuretics